High density electrode mapping catheter

ABSTRACT

Various embodiments of the present disclosure can include a flexible catheter tip. The flexible catheter tip can comprise an inboard understructure that defines a tip longitudinal axis, wherein the inboard understructure is formed from a first continuous element that includes a first rectangular cross-section. In some embodiments, an outboard understructure can extend along the tip longitudinal axis, wherein the outboard understructure is formed from a second continuous element that includes a second rectangular cross-section.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to U.S. provisional application No.62/244,630, filed 21 Oct. 2015, which is hereby incorporated byreference as though fully set forth herein. This application is relatedto U.S. application Ser. No. ______ entitled “HIGH DENSITY ELECTRODEMAPPING CATHETER” (CD-1064US02/065513-001523), filed on even dateherewith and incorporated by reference as though fully set forth herein.

FIELD OF THE DISCLOSURE

This disclosure relates to a high density electrode mapping catheter.

BACKGROUND ART

Catheters have been used for cardiac medical procedures for many years.Catheters can be used, for example, to diagnose and treat cardiacarrhythmias, while positioned at a specific location within a body thatis otherwise inaccessible without a more invasive procedure.

Conventional mapping catheters may include, for example, a plurality ofadjacent ring electrodes encircling the longitudinal axis of thecatheter and constructed from platinum or some other metal. These ringelectrodes are relatively rigid. Similarly, conventional ablationcatheters may comprise a relatively rigid tip electrode for deliveringtherapy (e.g., delivering RF ablation energy) and may also include aplurality of adjacent ring electrodes. It can be difficult to maintaingood electrical contact with cardiac tissue when using theseconventional catheters and their relatively rigid (or nonconforming),metallic electrodes, especially when sharp gradients and undulations arepresent.

Whether mapping or forming lesions in a heart, the beating of the heart,especially if erratic or irregular, complicates matters, making itdifficult to keep adequate contact between electrodes and tissue for asufficient length of time. These problems are exacerbated on contouredor trabeculated surfaces. If the contact between the electrodes and thetissue cannot be sufficiently maintained, quality lesions or accuratemapping are unlikely to result.

The foregoing discussion is intended only to illustrate the presentfield and should not be taken as a disavowal of claim scope.

BRIEF SUMMARY

Various embodiments of the present disclosure can include a flexiblecatheter tip. The flexible catheter tip can comprise an inboardunderstructure that defines a tip longitudinal axis, wherein the inboardunderstructure is formed from a first continuous element that includes afirst rectangular cross-section. In some embodiments, an outboardunderstructure can extend along the tip longitudinal axis, wherein theoutboard understructure is formed from a second continuous element thatincludes a second rectangular cross-section.

Various embodiments of the present disclosure can include an integratedelectrode structure. The integrated electrode structure can comprise acatheter shaft that includes a proximal end and a distal end, thecatheter shaft defining a catheter shaft longitudinal axis. A flexibletip portion can be located adjacent to the distal end of the cathetershaft. The flexible tip portion can comprise a flexible framework thatincludes an inboard understructure. The inboard understructure cancomprise a first continuous element that includes a first rectangularcross-section that extends along the shaft longitudinal axis; anoutboard understructure, the outboard understructure including a secondcontinuous element that includes a second rectangular cross-section thatextends along the shaft longitudinal axis; and a distal coupler thatconnects a distal end of the inboard understructure and a distal end ofthe outboard understructure.

Various embodiments of the present disclosure can include a medicaldevice. The medical device can comprise a catheter shaft that includes aproximal end and a distal end, the catheter shaft defining a cathetershaft longitudinal axis. The medical device can comprise a flexible tipportion, the flexible tip portion comprising a flexible framework thatincludes an inboard understructure, the inboard understructure includinga pair of proximal inboard mounting arms mounted in the distal end ofthe catheter shaft, wherein each of the proximal inboard mounting armsinclude an inboard frame lock portion; and an outboard understructure,the outboard understructure including a pair of proximal outboardmounting arms mounted in the distal end of the catheter shaft, whereineach of the proximal outboard mounting arms include an outboard framelock portion that corresponds with the inboard frame lock portion.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a top view of a high density electrode mapping catheter,according to various embodiments of the present disclosure.

FIG. 1B is an isometric side and top view of the high density electrodemapping catheter in FIG. 1A, according to various embodiments of thepresent disclosure.

FIG. 2A is an isometric side and top view of an inboard understructureof a high density electrode mapping catheter in FIG. 1A, according tovarious embodiments of the present disclosure.

FIG. 2B is a top view of the inboard understructure depicted in FIG. 2A,according to various embodiments of the present disclosure.

FIG. 2C is an enlarged view of an inboard frame lock portion of theinboard understructure depicted in FIG. 2A, according to variousembodiments of the present disclosure.

FIG. 2D is a cross-sectional view of a flared head portion of theinboard understructure depicted in FIG. 2B along line dd, according tovarious embodiments of the present disclosure.

FIG. 2E is a cross-sectional view of a flared head portion of theinboard understructure depicted in FIG. 2B along line ee, according tovarious embodiments of the present disclosure.

FIG. 2F is a cross-sectional view of a first inboard arm understructureof the inboard understructure depicted in FIG. 2B along line ff,according to various embodiments of the present disclosure.

FIG. 3A is a top view of an outboard understructure of a high densityelectrode mapping catheter depicted in FIG. 1A, according to variousembodiments of the present disclosure.

FIG. 3B is an enlarged view of an outboard frame lock portion of theoutboard understructure depicted in FIG. 3A, according to variousembodiments of the present disclosure.

FIG. 3C is a cross-sectional view of a head portion of the outboardunderstructure depicted in FIG. 3B along line gg, according to variousembodiments of the present disclosure.

FIG. 3D is a cross-sectional view of the first outboard armunderstructure of the outboard understructure depicted in FIG. 3A alongline hh, according to various embodiments of the present disclosure.

FIG. 4 depicts the inboard understructure in FIG. 2A and the outboardunderstructure in FIG. 3A with interlocking inboard frame lock portionand outboard frame lock portion, according to various embodiments of thepresent disclosure.

FIG. 5A depicts the inboard understructure in FIG. 2A and the outboardunderstructure depicted in FIG. 3A with interlocking inboard frame lockportion and outboard frame lock portion and a connector, according tovarious embodiments of the present disclosure.

FIG. 5B depicts the inboard understructure and outboard understructurein FIG. 5A with tubing disposed around the interlocking inboard framelock portion and outboard frame lock portion, according to variousembodiments of the present disclosure.

FIG. 6 depicts an isometric side and top view of a high densityelectrode mapping catheter being deflected, according to variousembodiments of the present disclosure.

FIG. 7A is a front view of a high density electrode mapping catheter ina first deflection state and a second deflection state, according tovarious embodiments of the present disclosure.

FIG. 7B is an isometric, side, front, and top view of the high densityelectrode mapping catheter in the second deflection state in FIG. 7A,according to various embodiments of the present disclosure.

FIG. 7C is a front view of the high density electrode mapping catheterdepicted in FIGS. 7A and 7B in the first deflection state and a thirddeflection state, according to various embodiments of the presentdisclosure.

FIG. 7D is an isometric, side, front, and top view of the high densityelectrode mapping catheter in the third deflection state in FIG. 7C,according to various embodiments of the present disclosure.

FIG. 8 depicts a top view of a high density electrode mapping catheterwith a flexible tip portion in a collapsed state, according to variousembodiments of the present disclosure.

DETAILED DESCRIPTION

The contents of International Application No. PCT/US2014/011940 entitledFlexible High-Density Mapping Catheter Tips and Flexible AblationCatheter Tips with Onboard High-Density Mapping Electrodes is herebyincorporated by reference.

FIG. 1A is a top view of a high density electrode mapping catheter 101and FIG. 1B is an isometric side and top view of the high densityelectrode mapping catheter 101, according to various embodiments of thepresent disclosure. In some embodiments, the high density electrodemapping catheter 101 can include a flexible tip portion 110 that forms aflexible array of microelectrodes 102-1, 102-2, 102-3, 102-4.Hereinafter, microelectrodes 102-1, 102-2, 102-3, 102-4 are referred toin the plural as microelectrodes 102. For ease of reference, only fourmicroelectrodes 102 are labeled in FIG. 1A, however, the high densitymapping catheter 101 can include more than four microelectrodes, asdepicted. This planar array (or ‘paddle’ configuration) ofmicroelectrodes 102 comprises four side-by-side,longitudinally-extending arms 103, 104, 105, 106, which can form aflexible framework on which the microelectrodes 102 are disposed. Thefour microelectrode-carrier arms comprise a first outboard arm 103, asecond outboard arm 106, a first inboard arm 104, and a second inboardarm 105, which can be connected via a distal coupler 109. These arms canbe laterally separated from each other.

Each of the four arms can carry a plurality of microelectrodes 102. Forexample, each of the four arms can carry microelectrodes 102 spacedalong a length of each of the four arms. Although each of the highdensity electrode mapping catheters 101 depicted in FIGS. 1A and 1Bdepict four arms, the high density electrode mapping catheters 101 couldcomprise more or fewer arms. Additionally, while the high densityelectrode mapping catheter 101 depicted in FIGS. 1A and 1B is depictedas including 18 electrodes (e.g., 5 microelectrodes on first outboardarm 103 and second outboard arm 106 and 4 microelectrodes on firstinboard arm 104 and second inboard arm 105), the catheters can includemore or fewer than 18 electrodes. In addition, the first outboard arm103 and second outboard arm 106 can include more or fewer than 5microelectrodes and the first inboard arm 104 and second inboard arm 105can include more or fewer than 4 microelectrodes).

In some embodiments, the microelectrodes 102 can be used in diagnostic,therapeutic, and/or mapping procedures. For example and withoutlimitation, the microelectrodes 102 can be used for electrophysiologicalstudies, pacing, cardiac mapping, and/or ablation. In some embodiments,the microelectrodes 102 can be used to perform unipolar or bipolarablation. This unipolar or bipolar ablation can create specific lines orpatterns of lesions. In some embodiments, the microelectrodes 102 canreceive electrical signals from the heart, which can be used forelectrophysiological studies. In some embodiments, the microelectrodes102 can perform a location or position sensing function related tocardiac mapping.

In some embodiments, the high density electrode mapping catheter 101 caninclude a catheter shaft 107. The catheter shaft 107 can include aproximal end and a distal end. The distal end can include a connector108, which can couple the distal end of the catheter shaft 107 to aproximal end of the planar array. The catheter shaft 107 can define acatheter shaft longitudinal axis aa, as depicted in FIG. 1A, along whichthe first outboard arm 103, first inboard arm 104, second inboard arm105, and second outboard arm 106 can generally extend parallel inrelation therewith. The catheter shaft 107 can be made of a flexiblematerial, such that it can be threaded through a tortuous vasculature ofa patient. In some embodiments, the catheter shaft 107 can include oneor more ring electrodes 111 disposed along a length of the cathetershaft 107. The ring electrodes 111 can be used for diagnostic,therapeutic, and/or mapping procedures, in an example.

As depicted in FIG. 1B, the flexible tip portion 110 can be adapted toconform to tissue (e.g., cardiac tissue). For example, when the flexibletip portion 110 contacts tissue, the flexible tip portion 110 candeflect, allowing the flexible framework to conform to the tissue. Insome embodiments, the arms (or the understructure of the arms)comprising the paddle structure (or multi-arm, electrode-carrying,flexible framework) at the distal end of the catheters depicted in FIGS.1A and 1B can be laser cut from a flexible or spring-like material suchas Nitinol and/or a flexible substrate, as discussed herein. In someembodiments, the arms (or the understructure of the arms) can be formedfrom a sheet of metal (e.g., Nitinol) with a uniform thickness.Different portions of the arms (or understructure of the arms) can heformed from the sheet (e.g., cut) such that the different portions ofthe arms have varying widths. The construction (including, for example,the length and/or diameter of the arms) and material of the arms can beadjusted or tailored to he created, for example, desired resiliency,flexibility, foldability, conformability, and stiffness characteristics,including one or more characteristics that may vary from the proximalend of a single arm to the distal end of that arm, or between or amongthe plurality of arms comprising a single paddle structure. Thefoldability of materials such as Nitinol and/or another type of flexiblesubstrate provide the additional advantage of facilitating insertion ofthe paddle structure into a delivery catheter or introducer, whetherduring delivery of the catheter into the body or removal of the catheterfrom the body at the end of a procedure.

Among other things, the disclosed catheters, with their plurality ofmicroelectrodes, are useful to (1) define regional propagation maps ofparticularly sized areas (e.g., one centimeter square areas) within theatrial walls of the heart; (2) identify complex fractionated atrialelectrograms for ablation; (3) identify localized, focal potentialsbetween the microelectrodes for higher electrogram resolution; and/or(4) more precisely target areas for ablation. These mapping cathetersand ablation catheters are constructed to conform to, and remain incontact with, cardiac tissue despite potentially erratic cardiac motion.Such enhanced stability of the catheter on a heart wall during cardiacmotion provides more accurate mapping and ablation due to sustainedtissue-electrode contact. Additionally, the catheters described hereinmay be useful for epicardial and/or endocardial use. For example, theplanar array embodiments depicted herein may be used in an epicardialprocedure where the planar array of microelectrodes is positionedbetween the myocardial surface and the pericardium. Alternatively theplanar array embodiments may be used in an endocardial procedure toquickly sweep and/or analyze the inner surfaces of the myocardium andquickly create high-density maps of the heart tissue's electricalproperties.

FIG. 2A is an isometric side and top view of an inboard understructure120 (also referred to herein as inner understructure) of the highdensity electrode mapping catheter depicted in FIG. 1A, according tovarious embodiments of the present disclosure. In some embodiments, theinboard understructure 120 can be formed from a flexible or spring-likematerial such as Nitinol and/or a flexible substrate, as discussedherein. In an example, the inboard understructure can be cut from aplanar sheet of material (e.g., planar substrate). The inboardunderstructure 120 can include a first inboard arm understructure 121and a second inboard arm understructure 122. Although not shown, theoutboard understructure (also referred to herein as outerunderstructure) that provides the understructure for the first outboardarm 103 and the second outboard arm 106 can be formed and/or processedin a manner analogous to that discussed in relation to the inboardunderstructure 120. Further, if the high density electrode mappingcatheter includes additional arms, those arms can be formed and/orprocessed in a manner analogous to that discussed in relation to theinboard understructure 120. For the sake of brevity, discussion isdirected towards the inboard understructure 120. As depicted, theinboard understructure 120 can include a first proximal inboard mountingarm 123 and a second proximal inboard mounting arm 124. The proximalinboard mounting arms can be inserted into a distal end of the catheter107 and through the connector 108 and can be used to connect theflexible tip portion 110 to the distal end of the catheter 107. In someembodiments, the proximal inboard mounting arms can be inserted througha torsional spacer, as discussed herein.

In some embodiments, the inboard understructure 120 can define a tiplongitudinal axis, depicted by line bb. In some embodiments, the inboardunderstructure 120 can be formed from a continuous element that includesa first rectangular cross-section. As used herein, a rectangularcross-section can include a square cross-section. For example, theinboard understructure 120 can include the first proximal inboardmounting arm 123 and second proximal inboard mounting arm 124, which canextend along the longitudinal axis. The inboard understructure 120 caninclude a first inboard arm understructure 121 that extends distallyfrom the first proximal inboard mounting arm 123 and can include asecond inboard arm understructure 122 that extends distally from thesecond proximal inboard mounting arm 124. In some embodiments, the firstinboard arm understructure 121 and the second inboard arm understructure122 can extend parallel to the tip longitudinal axis bb and to oneanother.

In some embodiments, a first transition understructure portion 126 canbe disposed between the first proximal inboard mounting arm 123 and thefirst inboard arm understructure 121. The first transitionunderstructure portion 126 can be laterally flared away from the tiplongitudinal axis bb. Additionally, a second transition understructureportion 127 can be disposed between the second proximal inboard mountingarm 124 and the second inboard arm understructure 122. The secondtransition understructure portion 128 can be laterally flared away fromthe tip longitudinal axis bb. In an example, the first transitionunderstructure portion 126 and the second transition understructureportion 128 can be flared away from one another.

In some embodiments, the inboard understructure 120 includes a flaredhead portion 130 that is connected to distal ends of the first andsecond inboard arm understructures 121, 122. In some embodiments, theflared head portion 130 can be formed from a first flared element 132and a second flared element 134. As the first flared element 132 and thesecond flared element 134 extend distally, the elements 132, 134 can belaterally flared away from the tip longitudinal axis bb and away fromone another, before extending toward the tip longitudinal axis bb andtoward one another. The first flared element 132 and the second flaredelement 134 can be connected along the tip longitudinal axis bb. In anexample, the inboard understructure can be symmetrical along either sideof the tip longitudinal axis bb.

In some embodiments, the proximal inboard portion of the inboard frameunderstructure 120 can include the first proximal inboard mounting arm123 and the second proximal inboard mounting arm 124. In an example, theproximal inboard portion of the inboard frame understructure 120 caninclude an inboard frame lock portion 136, which is further discussed inrelation to FIG. 2B.

FIG. 2B depicts a top view of the inboard understructure 120 depicted inFIG. 2A, according to various embodiments of the present disclosure.FIG. 2B depicts the inboard frame lock portion 136 of the proximalinboard portion of the inboard frame understructure 120. In someembodiments, a distal end of the first proximal inboard mounting arm 123and the second proximal inboard mounting arm 124 can be connected to aproximal end of the first transition understructure portion 126 and thesecond transition understructure portion 128, respectively. The firstproximal inboard mounting arm 123 can have a reduced lateral width withrespect to the first transition understructure portion 126 and thesecond proximal inboard mounting arm 124 can have a reduced lateralwidth with respect to the second transition understructure portion 128.In an example, the transition understructure portions 126, 128 and theproximal inboard mounting arms 123, 124 can be tapered at a taperedtransition area between the two elements, as further depicted in FIG.2C.

In some embodiments, a proximal end of the inboard frame lock portion136 can be connected to a proximal tail portion that includes a firstproximal tail 148 and a second proximal tail 150. The first proximaltail 148 can be connected to the first proximal inboard mounting arm 123and the second proximal tail 150 can be connected to the second proximalinboard mounting arm 124. In an example, the proximal inboard mountingarms 123, 124 and the proximal tails 148, 150 can be tapered at atapered tail transition area between the two elements, as furtherdepicted in FIG. 2C.

The inboard frame lock portion 136 can include a first pair of inboardframe lock tabs 138-1, 138-2 and a second pair of inboard frame locktabs 140-1, 140-2. In some embodiments, the inboard frame lock tabs138-1, 138-2, 140-1, 140-2 can laterally extend outward from the firstproximal inboard mounting arm 123 and the second proximal inboardmounting arm 124. In an example, the first pair of inboard frame locktabs 138-1, 138-2 can laterally extend from the first proximal inboardmounting arm 123 away from tip longitudinal axis bb; and the second pairof inboard frame lock tabs 140-1, 140-2 can laterally extend from thesecond proximal inboard mounting arm 124 away from tip longitudinal axisbb.

FIG. 2C is an enlarged view of an inboard frame lock portion 136 of theinboard understructure 120 depicted in FIG. 2A, according to variousembodiments of the present disclosure. As depicted with respect to afirst inboard frame lock tab 140-1, each of the inboard frame lock tabscan include a distal tab edge 142-1 and a proximal tab edge 142-2. Insome embodiments, the distal tab edge 142-1 and the proximal tab edge142-2 can be perpendicular to the tip longitudinal axis bb, although notdepicted. In some embodiments, the distal tab edge 142-1 and theproximal tab edge 142-2 can be formed at an angle θ′ with respect to oneanother. The angle θ′ can be in a range from 60 degrees to 10 degrees,in some embodiments. However, the angle θ′ can be less than 10 degreesor greater than 60 degrees in some embodiments. As depicted, the angleθ′ can be 30 degrees.

In some embodiments, a longitudinal length of each of the tabs can beapproximately 0.036 inches, although the tabs can have a shorter orlonger length. The tabs can be of a uniform longitudinal length in someembodiments and/or can be of different longitudinal lengths. In someembodiments, each of the tabs can have a lateral width of approximately0.013 inches, although the lateral width of each tab can be greater orsmaller. As depicted, the tabs can be longitudinally spaced apart. Forexample, with respect to the first inboard lock tab 140-1 and the secondinboard lock tab 140-2, the longitudinal center of each tab can belongitudinally spaced apart by approximately 0.08 inches, although thetabs can be spaced closer or father apart with respect to one another.

As previously discussed in relation to FIG. 2B, the transitionunderstructure portions 126, 128 and the proximal inboard mounting arms123, 124 can include tapered transition areas 144, 146 between thetransition understructure portions 126, 128 and the proximal inboardmounting arms 123, 124. The tapered transition areas 144, 146 can betapered in a distal to proximal direction, away from the tiplongitudinal axis bb. In some embodiments, the tapered transition areas144, 146 can be formed at an angle θ″ with respect to one another. Theangle θ″ can be in a range from 10 degrees to 180 degrees, in someembodiments. However, the angle θ″ can be less than 10 degrees orgreater than 180 degrees in some embodiments. In some embodiments, theangle θ″ can be approximately 25 degrees.

As previously discussed in relation to FIG. 2B, the proximal inboardmounting arms 123, 124 and the proximal tails 148, 150 can includetapered tail transition areas 152, 154 between the proximal inboardmounting arms 123, 124 and the proximal tails 148, 150. The tapered tailtransition areas 152, 154 can be tapered in a distal to proximaldirection, away from the tip longitudinal axis bb. In some embodiments,the tapered tail transition areas 152, 154 can be formed an angle θ′″with respect to one another. The angle θ′″ can be in a range from 10degrees to 180 degrees, in some embodiments. However, the angle θ′″ canbe less than 10 degrees or greater than 180 degrees in some embodiments.In some embodiments, the angle θ′″ can be approximately 25 degrees.

As previously discussed, each portion of the inboard frameunderstructure 120 (FIG. 2A, 2B), including the proximal tails 148, 150,proximal inboard mounting arms 123, 124, inboard arm understructures121, 122, and flared head portion 130 can be formed from a planarsubstrate. For example, the planar substrate can have a rectangularcross-section, which can be beneficial, as further described herein. Insome approaches, high density electrode mapping catheters can beassembled using tubular subassemblies for the inboard understructure andthe outboard understructure. One reason for the use of tubing whenassembling the understructures is to allow wire to be threaded throughthe tubing for connection of each individual microelectrode. Thisprocess can be labor and/or cost intensive, since each wire may beindividually threaded through the tubing and individually connected witheach microelectrode. Further, ensuring that a reliable electricalconnection is established between each microelectrode and its wire canbe challenging.

In addition, use of tubing can result in a less predictable deflectionof the flexible tip portion since the walls of the tubing may besymmetrical and are not biased to bend in a particular manner.Embodiments of the present disclosure can provide for a more predictabledeflection of the flexible tip portion 110. In addition, embodiments ofthe present disclosure can maintain a lateral spacing between electrodesdisposed on the inboard understructure and an outboard understructure,as further discussed herein.

As depicted in FIGS. 2A and 2B, the inboard understructure 120 (andalthough not depicted, the outboard understructure) can be formed from aplanar piece of material. In an example, the inboard understructure 120(and the outboard understructure) can be formed from an understructurewith a rectangular and/or square shaped cross-section. In someembodiments, the inboard understructure 120 and/or the outboardunderstructure can be a continuous element that is formed from a singleunitary piece of material. As used herein, a rectangular cross-sectioncan be defined as a cross-section having a greater width than thickness.However, in some embodiments, a rectangular cross-section can include across-section having a greater thickness than width. As used herein, asquare cross-section can be defined as a cross-section having a samewidth and thickness.

FIG. 2D depicts a cross-section of a flared head portion 130 of theinboard understructure 120 depicted in FIG. 2B along line dd, accordingto various embodiments of the present disclosure. In some embodiments,the cross-section of the flared head portion 130 can be rectangular, asdepicted in FIG. 2D, having a greater width than thickness. In someembodiments, the cross-section can be square, having a same width andthickness. In an example, a thickness at a longitudinal apex of theflared head portion 130 defined by line d_(t) can be in a range from0.0045 to 0.0065 inches. In some embodiments, the thickness at thelongitudinal apex of the flared head portion 130 can be approximately0.006 inches. In some embodiments, a longitudinal width (e.g., widthextending along the longitudinal axis bb) at the longitudinal apex ofthe flared head portion 130 defined by line d_(w) can be in a range from0.007 to 0.009 inches. In some embodiments, the longitudinal width atthe longitudinal apex of the flared head portion 130 can beapproximately 0.008 inches.

FIG. 2E depicts a cross-section of a flared head portion 130 of theinboard understructure 120 depicted in FIG. 2B along line ee, accordingto various embodiments of the present disclosure. In some embodiments,the cross-section at a lateral apex of the flared distal head portion130 can be square, as depicted in FIG. 2E, having a same width andthickness. In some embodiments, the cross-section at the lateral apex ofthe flared distal head portion 130 can be rectangular, having a greaterwidth than thickness. In some embodiments, a thickness at the lateralapex of the flared head portion 130 defined by line e_(t) can be in arange from 0.0045 to 0.0065 inches. In some embodiments, the thicknessat the lateral apex of the flared head portion 130 can be approximately0.006 inches. In some embodiments, a lateral width (e.g., widthextending transverse to the longitudinal axis bb) at the lateral apex ofthe flared head portion 130 defined by line e_(w) can be in a range from0.005 to 0.007 inches. In some embodiments, the lateral width at thelateral apex of the flared head portion 130 can be approximately 0.006inches.

FIG. 2F depicts a cross-section of a first inboard arm understructure121 of the inboard understructure 120 depicted in FIG. 2B along line ff,according to various embodiments of the present disclosure. In someembodiments, the cross-section of the first inboard arm understructure121 can be rectangular, as depicted in FIG. 2F, having a greater widththan thickness. In some embodiments, the cross-section can be square,having a same width and thickness. In some embodiments, a thickness atthe first inboard arm understructure 121 defined by line f_(t) can be ina range from 0.0045 to 0.0065 inches. In some embodiments, the thicknessat the first inboard arm understructure 121 can be approximately 0.006inches. In some embodiments, a lateral width at the first inboard armunderstructure 121 defined by line f_(w) can be in a range from 0.0125to 0.0135 inches. In some embodiments, the lateral width at the lateralapex of the flared head portion 130 can be approximately 0.013 inches.The second inboard arm understructure 122 can be of the same dimensionsas the first inboard arm understructure 121. Accordingly, in someembodiments, the inboard understructure 120 can have a uniform thicknessand a varying width.

FIG. 3A is a top view of an outboard understructure 170 (also referredto herein as outer understructure) of a high density electrode mappingcatheter in FIG. 1A, according to various embodiments of the presentdisclosure. In some embodiments, the outboard understructure 170 can beformed from a flexible or spring-like material such as Nitinol and/or aflexible substrate, as previously discussed with respect to the inboardunderstructure. The outboard understructure 170 can include a firstoutboard arm understructure 172 and a second outboard arm understructure174. As depicted, the outboard understructure 170 can include a firstproximal inboard mounting arm 176 and a second proximal inboard mountingarm 178. The proximal inboard mounting arms 176, 178 can be insertedinto a distal end of the catheter 107 (FIG. 1A, 1B) and can be used toconnect the flexible tip portion 110 (FIG. 1A, 1B) to the distal end ofthe catheter 107. In some embodiments, the proximal outboard mountingarms 176, 178 can be inserted through a torsional spacer, as discussedherein.

In some embodiments, the outboard understructure 170 can define a tiplongitudinal axis, depicted by line b′b′. In some embodiments, theoutboard understructure 170 can be formed from a continuous element thatincludes a first rectangular cross-section. For example, the outboardunderstructure 170 can include the first proximal outboard mounting arm176 and second proximal outboard mounting arm 178, which can extendalong the tip longitudinal axis. The outboard understructure 170 caninclude a first outboard arm understructure 172 that extends distallyfrom the first proximal inboard mounting arm 176 and can include asecond outboard arm understructure 174 that extends distally from thesecond proximal outboard mounting arm 178. In some embodiments, thefirst outboard arm understructure 172 and the second outboard armunderstructure 174 can extend parallel to the tip longitudinal axis b′b′and to one another.

In some embodiments, a first outboard transition understructure portion180 can be disposed between the first proximal outboard mounting arm 176and the first outboard arm understructure 172. The first outboardtransition understructure portion 180 can be laterally flared away fromthe tip longitudinal axis b′b′. Additionally, a second outboardtransition understructure portion 181 can be disposed between the secondproximal outboard mounting arm 178 and the second outboard armunderstructure 174. The second outboard transition understructureportion 181 can be laterally flared away from the tip longitudinal axisb′b′. In an example, the first outboard transition understructureportion 180 and the second outboard transition understructure portion181 can be flared away from one another.

In some embodiments, the outboard understructure 170 includes a headportion 182 that is connected to distal ends of the first and secondoutboard arm understructures 172, 174. In some embodiments, the headportion 182 can be formed from a first tapered element 184 and a secondtapered element 186 that each extend distally toward the tiplongitudinal axis b′b′ and converge at the longitudinal axis b′b′. In anexample, the outboard understructure 170 can be symmetrical along eitherside of the tip longitudinal axis b′b′.

In some embodiments, the proximal outboard portion of the inboard frameunderstructure 170 can include the first proximal outboard mounting arm176 and the second proximal outboard mounting arm 178. In an example,the proximal outboard portion of the outboard frame understructure 170can include an outboard frame lock portion 188, which is furtherdiscussed in relation to FIG. 3B.

In some embodiments, a distal end of the first proximal outboardmounting arm 176 and the second proximal outboard mounting arm 178 canbe connected to a proximal end of the first outboard transitionunderstructure portion 180 and the second outboard transitionunderstructure portion 181, respectively. The first proximal outboardmounting arm 176 can have a reduced lateral width with respect to thefirst outboard transition understructure portion 180 and the secondproximal outboard mounting arm 178 can have a reduced lateral width withrespect to the second outboard transition understructure portion 181. Inan example, the outboard transition understructure portions 180, 181 andthe proximal outboard mounting arms 176, 178 can be tapered at anoutboard tapered transition area between the two elements, as furtherdepicted in FIG. 3B.

In some embodiments, a proximal end of the outboard frame lock portion188 can be connected to a proximal outboard tail portion that includes afirst proximal outboard tail 189 and a second proximal outboard tail190. The first proximal outboard tail 189 can be connected to the firstproximal outboard mounting arm 176 and the second proximal outboard tail190 can be connected to the second proximal outboard mounting arm 178.In an example, the proximal outboard mounting arms 176, 178 and theproximal outboard tails 189, 190 can be tapered at a tapered outboardtail transition area between the two elements, as further depicted inFIG. 3B.

The outboard frame lock portion 188 can include a first pair of outboardframe lock tabs 192-1, 192-2 and a second pair of outboard frame locktabs 194-1, 194-2. In some embodiments, the outboard frame lock tabs192-1, 192-2, 194-1, 194-2 can laterally extend inward from the firstproximal outboard mounting arm 176 and the second proximal inboardmounting arm 178. In an example, the first pair of outboard frame locktabs 192-1, 192-2 can laterally extend from the first proximal inboardmounting arm 176 toward the tip longitudinal axis b′b; and the secondpair of outboard frame lock tabs 194-1, 194-2 can laterally extend fromthe second proximal inboard mounting arm 178 toward the tip longitudinalaxis b′b′.

FIG. 3B is an enlarged view of an outboard frame lock portion 188 of theoutboard understructure 170 depicted in FIG. 3A, according to variousembodiments of the present disclosure. As depicted with respect to afirst outboard frame lock tab 194-1, each of the outboard frame locktabs can include a distal tab edge 200-1 and a proximal tab edge 200-2.In some embodiments, the distal tab edge 200-1 and the proximal tab edge200-2 can be perpendicular to the tip longitudinal axis b′b′, althoughnot depicted. In some embodiments, the distal tab edge 200-1 and theproximal tab edge 200-2 can be formed at an angle θ^(A) with respect toone another. The angle θ^(A) can be in a range from 60 degrees to 10degrees, in some embodiments. However, the angle θ′ can be less than 10degrees or greater than 60 degrees in some embodiments. As depicted, theangle θ′ can be 30 degrees. In some embodiments, the angle θ^(A) can bethe same as the angle θ′, to ensure that inboard frame lock portion 136fits together with the outboard frame lock portion 188.

In some embodiments, a first pair of lock grooves 196-1, 196-2 and asecond pair of lock grooves 198-1, 198-2 can be formed in the outboardframe lock portion 188. In an example, the lock grooves can be formed onthe inside (e.g., side towards the tip longitudinal axis b′b′) of eachfirst and second proximal outboard mounting arms 178. In an example, thefirst and second pairs of inboard frame lock tabs 138-1, 138-2, 140-1,140-2 (FIG. 2B, 2C) can be inserted into respective ones of the lockgrooves 196-1, 196-2, 198-1, 198-2, as further discussed herein.

In some embodiments, the transition understructure portions 180, 181 andthe proximal outboard mounting arms 176, 187 can include taperedtransition areas 202, 204 between the transition understructure portions180, 181 and the proximal inboard mounting arms 176, 178. The taperedtransition areas 202, 204 can be tapered in a distal to proximaldirection, toward the tip longitudinal axis b′b′. In some embodiments,the tapered transition areas 202, 204 can be formed at an angle θ^(B)with respect to one another. The angle θ^(B) can be in a range from 10degrees to 180 degrees, in some embodiments. However, the angle θ^(B)can be less than 10 degrees or greater than 180 degrees in someembodiments. In some embodiments, the angle θ^(B) can be approximately25 degrees.

As previously discussed in relation to FIG. 3A, the proximal outboardmounting arms 176, 178 and the proximal outboard tails 189, 190 caninclude tapered tail transition areas 206, 208 between the proximaloutboard mounting arms 176, 178 and the proximal outboard tails 189,190. The tapered tail transition areas 206, 208 can be tapered in adistal to proximal direction, toward the tip longitudinal axis b′b′. Insome embodiments, the tapered tail transition areas 206, 208 can beformed at an angle θ^(C) with respect to one another. The angle θ^(C)can be in a range from 10 degrees to 180 degrees, in some embodiments.However, the angle θ^(C) can be less than 10 degrees or greater than 180degrees in some embodiments. In some embodiments, the angle θ^(C) can beapproximately 46 degrees.

As previously discussed, each portion of the outboard frameunderstructure 170, including the proximal tails 189, 190, proximaloutboard mounting arms 176, 178, outboard arm understructures 172, 174,and head portion 182 can be formed from a planar substrate. For example,the planar substrate can have a rectangular cross-section, which can bebeneficial, as further described herein. As previously discussed, insome approaches, high density electrode mapping catheters can beassembled using tubular subassemblies for the inboard understructure andthe outboard understructure. However, use of tubing can result in a lesspredictable deflection of the flexible tip portion since the walls ofthe tubing may be symmetrical and are not biased to bend in a particularmanner. Embodiments of the present disclosure can provide for a morepredictable deflection of the flexible tip portion 110 and the inboardunderstructure 120 (FIGS. 2A, 2B) and the outboard understructure 170.

As depicted in FIGS. 3A and 3B, the outboard understructure 170 can beformed from a planar piece of material. In an example, the outboardunderstructure 170 can be formed from an understructure with arectangular and/or square shaped cross-section. In some embodiments, theoutboard understructure 170 can be a continuous element that is formedfrom a single unitary piece of material.

FIG. 3C depicts a cross-section of a head portion 182 of the outboardunderstructure 170 depicted in FIG. 3B along line gg, according tovarious embodiments of the present disclosure. In some embodiments, athickness at a longitudinal apex of the head portion 182 defined by lineg_(t) can be in a range from 0.0045 to 0.0065 inches. In someembodiments, the thickness at the longitudinal apex of the flared headportion 130 can be approximately 0.006 inches. In some embodiments, alongitudinal width (e.g., width extending along the longitudinal axisb′b′) at the longitudinal apex of the head portion 182 defined by lineg, can be in a range from 0.0075 to 0.0085 inches. In some embodiments,the longitudinal width at the longitudinal apex of the flared headportion 130 can be approximately 0.008 inches.

FIG. 3D depicts a cross-section of the first outboard arm understructure172 of the outboard understructure 170 depicted in FIG. 3A along linehh, according to various embodiments of the present disclosure. In someembodiments, a thickness at the first outboard arm understructure 172defined by line h_(t) can be in a range from 0.0045 to 0.0065 inches. Insome embodiments, the thickness at the first outboard arm understructure172 can be approximately 0.006 inches. In some embodiments, a lateralwidth (e.g., width extending transverse to the longitudinal axis b′b′)at the first outboard arm understructure 172 defined by line h_(w) canbe in a range from 0.0125 to 0.0135 inches. In some embodiments, thelateral width at the first outboard arm understructure 172 can beapproximately 0.013 inches. The second outboard arm understructure 174can have a similar construction as discussed in relation to the firstoutboard arm understructure 172.

FIG. 4 depicts the inboard understructure 120 depicted in FIG. 2A andthe outboard understructure 170 depicted in FIG. 3A with interlockinginboard frame lock portion 136 and outboard frame lock portion 188,according to various embodiments of the present disclosure. The inboardunderstructure 120 and the outboard understructure 170 include thosefeatures previously discussed in relation to FIGS. 2A to 3D. Asdepicted, the inboard frame lock portion 136 is depicted as interlockingwith the outboard frame lock portion 188. In an example, the inboardframe lock tabs 138-1, 138-2, 140-1, 140-2 are disposed in the lockgrooves 196-1, 196-2, 198-1, 198-2 and adjacent to the outboard framelock tabs 192-1, 192-2, 194-1, 194-2. This can create an interlockingfit between the inboard frame lock portion 136 and the outboard framelock portion 188. The interlocking fit can prevent longitudinal movementof the inboard understructure 120 with respect to the outboardunderstructure 170, in some embodiments. Although four inboard framelock tabs 138-1, 138-2, 140-1, 140-2 and four outboard frame lock tabs192-1, 192-2, 194-1, 194-2 are depicted, greater than or fewer than fourinboard and/or outboard frame lock tabs can be included on the inboardand outboard understructures. In some embodiments, the inboard framelock portion 136 can be disposed in the outboard frame lock portion 188such that a top surface of the inboard frame lock portion 136 is flushwith a top surface of the outboard frame lock portion 188; and a bottomsurface of the inboard frame lock portion 136 is flush with a bottomsurface of the outboard frame lock portion 188.

In some embodiments, the first and second outboard transitionunderstructure portions 126, 128 can be formed at descending angles in adistal to proximal direction and the understructure forming the headportion 182 and flared head portion 130 can be formed at ascendingangles in a distal to proximal direction. This can increase an ease ofdelivery and withdrawal through a sheath and also during manufacturingof the electrodes that are disposed on the inboard understructure 120and/or the outboard understructure 170. For example, during assembly,electrodes can be slid over the understructure in a proximal to distaldirection. The angle of the outboard transition understructure can allowfor easier sliding of the electrodes over the understructure.

FIG. 5A depicts the inboard understructure 120 depicted in FIG. 2A andthe outboard understructure 170 depicted in FIG. 3A with interlockinginboard frame lock portion 136 and outboard frame lock portion 188 and aconnector 212, according to various embodiments of the presentdisclosure. A gap is depicted between the inboard frame lock portion 136and the outboard frame lock portion 188. In some embodiments, aconnector 212 can be disposed at a distal end of the inboard frame lockportion 136 and outboard frame lock portion 188, as depicted. Theinboard understructure 120 and the outboard understructure 170 canlongitudinally extend through the connector 212.

In an example, the connector 212 can include a connector head portion214 and a mount portion 216 and can be formed from a polymer or metal.In some embodiments, the mount portion 216 can be cylindrical in shapeand can be sized to be inserted into a distal end of a catheter shaft.In some embodiments, an adhesive can be applied between the cathetershaft and the mount portion 216 and/or a mechanical connector can beused to secure the catheter shaft to the mount portion 216. In someembodiments, a series of circumferential grooves can extend around acircumference of the mount portion 216. The circumferential grooves canprovide an area for an adhesive to collect when connecting the connector212 to the catheter shaft. In some embodiments, the connector headportion 214 can have an outer diameter that is greater than the mountportion 216 and can be equal to an outer diameter of a catheter shaft. Adistal end of the head portion 214 can be dome shaped, as depicted, toform an atraumatic tip.

FIG. 5B depicts the inboard understructure 120 and outboardunderstructure 170 depicted in FIG. 5A with tubing 220, 222 disposedaround the interlocking inboard frame lock portion 136 and outboardframe lock portion 188, according to various embodiments of the presentdisclosure. In some embodiments, a first section of tubing 220 and asecond section of tubing 222 can each be disposed around theinterlocking portions of the inboard frame lock portion 136 and outboardframe lock portion 188. The interlocking portions of the inboard framelock portion 136 and the outboard frame lock portion 188 disposed withinthe first and second section of tubing 220, 222 is depicted in phantom.In an example, the first section of tubing 220 and the second section oftubing 222 can include an inner diameter that is the same or larger thana lateral width of the interlocking portions of the inboard frame lockportion 136 and the outboard frame lock portion 188. The first sectionof tubing 220 and the second section of tubing 222 can be slidlongitudinally over a proximal portion of the interlocking portions ofthe inboard frame lock portion 136 and the outboard frame lock portion188, such that the interlocking portions of the inboard frame lockportion 136 and the outboard frame lock portion 188 are disposed inrespective lumens of the first and second sections of tubing 220, 222.

Although the first and second sections of tubing 220, 222 are depictedas extending over the proximal portion of the interlocking portions ofthe inboard frame lock portion 136 and the outboard frame lock portion188, the first and second section of tubing 220, 222 can extend moredistally. For example, the first and second section of tubing 220, 222can extend to the proximal end of the coupler 212. In some embodiments,the lumens of the first and second sections of tubing 220, 222 can befilled with an adhesive to secure the interlocking portions of theinboard frame lock portion 136 and the outboard frame lock portion 188.In some embodiments, the first and second sections of tubing 220, 222can be heat shrink tubing, which can be heated and shrunk to secure theinterlocking portions of the inboard frame lock portion 136 and theoutboard frame lock portion 188.

FIG. 6 depicts an isometric side and top view of a high densityelectrode mapping catheter 230 being deflected, according to variousembodiments of the present disclosure. In some embodiments, the highdensity electrode mapping catheter includes a flexible tip portion 232that forms a flexible array of microelectrodes 334, which is disposed ata distal end of a catheter shaft 228. This planar array (or ‘paddle’configuration) of microelectrodes 234 comprises four side-by-side,longitudinally-extending arms 236, 238, 240, 242, which can form aflexible framework on which the microelectrodes 234 are disposed. Thefour microelectrode-carrier arms comprise a first outboard arm 236, asecond outboard arm 242, a first inboard arm 238, and a second inboardarm 240. These arms can be laterally separated from each other. Theinboard portion of the flexible tip 232 can include a flared headportion 244 and the outboard portion of the flexible tip 232 can includea head portion 246. The first outboard arm 236 and the second outboardarm 242 can include an outboard understructure and the first inboard arm238 and the second inboard arm 240 can include an inboardunderstructure, as previously discussed. The first and second inboardarms 238, 240, as well as the flared head portion 244, can include afirst and second inboard arm understructure that is formed from anelement that includes a rectangular cross-section and the first andsecond outboard arms 236, 242. as well as the head portion 246, caninclude a first and second outboard arm understructure that is formedfrom an element that includes a rectangular cross-section, as previouslydiscussed herein. In some embodiments, the flexible tip portion 232 caninclude a first outboard transition portion 248 and a second outboardtransition portion 254. In some embodiments, the flexible tip portion232 can include a first inboard transition portion 250 and a secondinboard transition portion 252.

in some embodiments, as previously discussed and depicted in relation toFIGS. 2A to 3D, the understructure that forms the flared head portion244 can have a reduced cross-sectional width in relation to theunderstructure that forms the inboard arms 238, 240. In addition, theunderstructure that forms the head portion 246 can have a reducedcross-sectional width in relation to the understructure that forms theoutboard arms 236. 242. This reduced cross-sectional width of theunderstructure forming the flared head portion 244 and the head portion246 can increase a resiliency of the head portions 244, 246 and causethe head portions 244, 246 to be less traumatic to cardiac tissue. Forexample, because of the reduced cross-sectional width, the head portionscan have an increased flexibility and a reduced amount of force can berequired to deflect the head portions 244, 246, providing for anatraumatic design.

In some embodiments, as previously discussed and depicted in relation toFIGS. 2A to 3D, the first outboard arm 236, second outboard arm 242,first outboard transition portion 248, and second outboard transitionportion 254 can be formed from an understructure that has an increasedcross-sectional width in relation to the understructure that forms thehead portion 246. In addition, the first inboard arm 238, second inboardarm 240, first inboard transition portion 250, and second inboardtransition portion 252 can be formed from an understructure that has anincreased cross-sectional width in relation to the understructure thatforms the flared head portion 244. In some embodiments, the increasedcross-sectional width of the understructure that forms the inboard andoutboard arms, as well as the inboard and outboard transition portionscan provide for a more gradual bend of the flexible tip portion 232located proximal to the flared head portion 244 and the head portion246, The more gradual bend can be beneficial in making homogeneous (e.g.uniform) cardiac tissue contact with all of the electrodes disposed onthe inboard and outboard arms and/or the inboard and outboard transitionportions.

In addition, because the understructure that forms each component of theflexible tip portion 232 includes a rectangular cross-section, thelateral spacing between each one of the microelectrodes disposed on theflexible tip portion 232 can be maintained when various lateral forces(e.g., pinch) are applied to the flexible tip portion, which can beencountered in relation to various anatomical conditions. For example,with further mference to FIG. 1, an electrode spacing can be maintainedeven when a lateral force is applied to the flexible tip portion 110 inthe direction of arrows 112-1, 112-2. In some approaches where anunderstructure that forms the inboard and outboard arms is made from atubular material, when a lateral force is applied to the inboard and/oroutboard arms, the arms can bend inward toward the longitudinal axis aa.For example, if the outboard arms 103, 106 included a tubularunderstructure, the outboard arms 103, 106 would be pushed laterallyinward toward the longitudinal axis and towards the inboard arms 104,105 in response to a force being applied in the direction of arrows112-1, 112-2. This can reduce a spacing between the microelectrodesdisposed on the outboard arms and the microelectrodes disposed on theinboard arms, thus causing interference between the microelectrodes.However, embodiments of the present disclosure can maintain the spacingbetween the inboard arms and the outboard arms, as well as themicroelectrodes disposed on the inboard arms and the outboard arms,

In an example, as discussed herein, the understructure that forms theinboard arms 104, 105 and the outboard arms 103, 106 can have arectangular cross-section, as discussed in relation to FIGS. 2A to 3D.For instance, the understructure that forms the inboard arms 104, 105and the outboard arms 103, 106 can have an increased lateral widthversus a lateral width of the understructure that forms the headportions. Additionally, a dimension of the lateral width can be greaterthan a dimension of the thickness of the understructure that forms theinboard arms 104, 105 and the outboard arms 103, 106. This can preventthe outboard arms 103, 106 from deflecting inward toward thelongitudinal axis aa, thus maintaining a lateral spacing between themicroelectrodes 102. For example, a lateral spacing can be maintainedbetween a first microelectrode 102-1 disposed on the first outboard arm103 and a third microelectrode 102-3 disposed on the first inboard arm104 in the presence of a lateral force in the direction of arrows 112-1,112-2. Likewise, a lateral spacing can be maintained between a secondmicroelectrode 102-2 disposed on the first outboard arm 103 and a fourthmicroelectrode 102-4 disposed on the first inboard arm 104 in thepresence of a lateral force in the direction of arrows 112-1, 112-2.

Instead of deflecting laterally, the inboard understructure and/or theoutboard understructure can deflect upward or downward, thus avoidingelectrode to electrode contact, as further discussed in relation toFIGS. 7A to 7D. FIG. 7A depicts a front view of a high density electrodemapping catheter 260 in a first deflection state 262-1 and a seconddeflection state 262-2, according to various embodiments of the presentdisclosure. The high density electrode mapping catheter 260 includes anoutboard portion 264 formed from an outboard understructure. Theoutboard understructure can be formed from an element with a rectangularcross-section, as discussed herein. The high density electrode mappingcatheter 260 can include a connector 266 disposed on the distal end of acatheter shaft 282 (depicted in FIGS. 7B and 7D), as well as a distalcoupler 268 that couples an inboard portion 280 (depicted in FIGS. 7Band 7D) with the outboard portion 264. As depicted, when an amount oflateral force applied to the outboard portion 264 is zero, theunderstructure of the outboard portion 264 can be in a first deflectionstate 262-1 (e.g., a natural deflection state), extending laterally withrespect to a longitudinal axis of the high density electrode mappingcatheter 260. However, when a lateral force is applied to the outboardportion 264 in the direction of arrows 270-1, 270-2, the outboardportion can deflect upward into a second deflection state 262-2,depicted in phantom. Thus, the outboard portion 264 can deflect upwardinto the second deflection state 262-2, rather than deflecting laterallyinward toward a longitudinal axis of the high density electrode mappingcatheter 260.

FIG. 7B depicts an isometric, side, front, and top view of the highdensity electrode mapping catheter 260 in the second deflection state262-2 in FIG. 7A, according to various embodiments of the presentdisclosure. The high density electrode mapping catheter 260 includesthose features discussed in relation to FIG. 7A, for example, the highdensity electrode mapping catheter 260 includes the outboard portion264, the inboard portion 280, distal coupler 268, connector 266 andcatheter shaft 282. As depicted, the outboard portion 264 and theinboard portion 280 can be deflected upward in response to a lateralforce being subjected to the high density mapping catheter 260 (e.g.,the outboard portion 264 and/or inboard portion 280). In an example,because the understructure that forms a first outboard arm 282 andsecond outboard arm 288 and the understructure that forms a firstinboard arm 284 and second inboard arm 286 of the high density electrodemapping catheter 260 have a rectangular cross-section (e.g., have anincreased lateral width versus thickness), the first and second outboardarms 282, 288 can deflect upward instead of deflecting laterally inwardtoward a longitudinal axis of the high density electrode mappingcatheter 260.

FIG. 7C depicts a front view of the high density electrode mappingcatheter 260 depicted in FIGS. 7A and 7B in the first deflection state262-1 and a third deflection state 262-3, according to variousembodiments of the present disclosure. The high density electrodemapping catheter 260 includes the outboard portion 264 formed from anoutboard understructure, connector 266 disposed on the distal end of thecatheter shaft 282 (depicted in FIGS. 7B and 7D), as well as the distalcoupler 268 that couples an inboard portion 280 (depicted in FIGS. 7Band 7D) with the outboard portion 264. As depicted, when an amount oflateral force applied to the outboard portion 264 is zero, theunderstructure of the outboard portion 264 can be in a first deflectionstate 262-1 (e.g., a natural deflection state), extending laterally withrespect to a longitudinal axis of the high density electrode mappingcatheter 260. However, when a lateral force is applied to the outboardportion 264 in the direction of arrows 270-1′, 270-2′, the outboardportion 264 can deflect downward into a third deflection state 262-3,depicted in phantom. Thus, the outboard portion 264 can deflect downwardinto the third deflection state 262-3, rather than deflecting laterallyinward toward a longitudinal axis of the high density electrode mappingcatheter 260. In some embodiments, a deciding factor associated withwhether the outboard portion 264 or inboard portion 280 of the highdensity electrode mapping catheter 260 will deflect downward or upwardcan be associated with an angle at which the lateral force is applied tothe outboard portion 264 and/or inboard portion 280.

FIG. 7D depicts an isometric, side, front, and top view of the highdensity electrode mapping catheter 260 in the third deflection state262-3 in FIG. 7C, according to various embodiments of the presentdisclosure. The high density electrode mapping catheter 260 includesthose features discussed in relation to FIG. 7C, for example, the highdensity electrode mapping catheter 260 includes the outboard portion264, the inboard portion 280, distal coupler 268, connector 266 andcatheter shaft 282. As depicted, the outboard portion 264 and theinboard portion 280 can be deflected downward in response to a lateralforce being subjected to the high density mapping catheter 260 (e.g.,the outboard portion 264 and/or inboard portion 280). In an example,because the understructure that forms the first outboard arm 282 andsecond outboard arm 288 and the understructure that forms the firstinboard arm 284 and second inboard arm 286 of the high density electrodemapping catheter 260 have a rectangular cross-section (e.g., have anincreased lateral width versus thickness), the first and second outboardarms 282, 288 can deflect downward instead of deflecting laterallyinward toward a longitudinal axis of the high density electrode mappingcatheter 260. This can maintain a spacing between microelectrodesdisposed on the inboard and outboard arms.

FIG. 8 depicts a top view of a high density electrode mapping catheter300 with a flexible tip portion 304 in a collapsed state, according tovarious embodiments of the present disclosure. In some embodiments, thehigh density electrode mapping catheter 300 can include a catheter shaft302. The catheter shaft 302 can include a proximal end and a distal end.The distal end can include a connector 306, which can couple the distalend of the catheter shaft 302 to a proximal end of the flexible tipportion 304 (e.g., planar array). The flexible tip portion 304 caninclude an outboard portion that includes a first outboard arm 308,second outboard arm 214, and head portion 318 and can include an inboardportion that includes a first inboard arm 310 and second inboard arm 312and a flared head portion 316. The head portion 318 and the flared headportion 316 can be connected at their respective distal ends via adistal coupler 320, in some embodiments.

As depicted, the flexible tip portion 304 is in a stored state. Theflexible tip portion 304 can be in such a state when it is stored in asheath for introduction into a body, in an example. Upon introduction ofthe flexible tip portion 304 into the sheath, the outboard portion andinboard portion of the flexible tip portion 304 can be laterallycompressed toward a longitudinal axis of the high density electrodemapping catheter 300. For example, the outboard portion and inboardportion of the flexible tip portion 304 can be laterally compressed bythe inner walls of the sheath. In some embodiments, the flared headportion 316 of the inboard. portion can be straightened as the inboardportion and the outboard portion are laterally compressed toward thelongitudinal axis of the flexible tip portion 304. In some approachesthat do not have a flared head portion 316, as the inboard portion andthe outboard portion are laterally compressed, a hook can be formed inthe distal end of the flexible tip portion 304. Embodiments of thepresent disclosure can include for the flared head portion 316, whichcan provide for a slack portion, which can be lengthened when theinboard portion and the outboard portion are laterally compressed. Forexample, the flared distal head (e.g., spade shaped portion) cancompensate for the extra length needed to match the outer frame totallength when folded during delivery and/or withdrawal through the sheath,which can prevent the hook from forming.

Embodiments are described herein of various apparatuses, systems, and/ormethods. Additional aspects of the present disclosure will be madeapparent upon review of the material in Appendix A, attached herewith.Numerous specific details are set forth to provide a thoroughunderstanding of the overall structure, function, manufacture, and useof the embodiments as described in the specification and illustrated inthe accompanying drawings. It will be understood by those skilled in theart, however, that the embodiments may be practiced without suchspecific details. In other instances, well-known operations, components,and elements have not been described in detail so as not to obscure theembodiments described in the specification. Those of ordinary skill inthe art will understand that the embodiments described and illustratedherein are non-limiting examples, and thus it may be appreciated thatthe specific structural and functional details disclosed herein may berepresentative and do not necessarily limit the scope of theembodiments, the scope of which is defined solely by the appendedclaims.

Reference throughout the specification to “various embodiments,” “someembodiments,” “one embodiment,” or “an embodiment”, or the like, meansthat a particular feature, structure, or characteristic described inconnection with the embodiment(s) is included in at least oneembodiment. Thus, appearances of the phrases “in various embodiments,”“in some embodiments,” “in one embodiment,” or “in an embodiment,” orthe like, in places throughout the specification, are not necessarilyall referring to the same embodiment. Furthermore, the particularfeatures, structures, or characteristics may be combined in any suitablemanner in one or more embodiments. Thus, the particular features,structures, or characteristics illustrated or described in connectionwith one embodiment may be combined, in whole or in part, with thefeatures, structures, or characteristics of one or more otherembodiments without limitation given that such combination is notillogical or non-functional.

It will be appreciated that the terms “proximal” and “distal” may beused throughout the specification with reference to a clinicianmanipulating one end of an instrument used to treat a patient. The term“proximal” refers to the portion of the instrument closest to theclinician and the term “distal” refers to the portion located furthestfrom the clinician. It will be further appreciated that for concisenessand clarity, spatial terms such as “vertical,” “horizontal,” “up,” and“down” may be used herein with respect to the illustrated embodiments.However, surgical instruments may be used in many orientations andpositions, and these terms are not intended to be limiting and absolute.

Although at least one embodiment for a high density electrode mappingcatheter has been described above with a certain degree ofparticularity, those skilled in the art could make numerous alterationsto the disclosed embodiments without departing from the spirit or scopeof this disclosure. All directional references (e.g., upper, lower,upward, downward, left, right, leftward, rightward, top, bottom, above,below, vertical, horizontal, clockwise, and counterclockwise) are onlyused for identification purposes to aid the reader's understanding ofthe present disclosure, and do not create limitations, particularly asto the position, orientation, or use of the devices. Joinder references(e.g., affixed, attached, coupled, connected, and the like) are to beconstrued broadly and may include intermediate members between aconnection of elements and relative movement between elements. As such,joinder references do not necessarily infer that two elements aredirectly connected and in fixed relationship to each other. It isintended that all matter contained in the above description or shown inthe accompanying drawings shall be interpreted as illustrative only andnot limiting. Changes in detail or structure may be made withoutdeparting from the spirit of the disclosure as defined in the appendedclaims.

Any patent, publication, or other disclosure material, in whole or inpart, that is said to be incorporated by reference herein isincorporated herein only to the extent that the incorporated materialsdoes not conflict with existing definitions, statements, or otherdisclosure material set forth in this disclosure. As such, and to theextent necessary, the disclosure as explicitly set forth hereinsupersedes any conflicting material incorporated herein by reference.Any material, or portion thereof, that is said to be incorporated byreference herein, but which conflicts with existing definitions,statements, or other disclosure material set forth herein will only beincorporated to the extent that no conflict arises between thatincorporated material and the existing disclosure material.

What is claimed:
 1. A flexible catheter tip, comprising: an inboardunderstructure that defines a tip longitudinal axis, wherein the inboardunderstructure is formed from a first continuous element that includes afirst rectangular cross-section; and an outboard understructure thatextends along the tip longitudinal axis, wherein the outboardunderstructure is formed from a second continuous element that includesa second rectangular cross-section.
 2. The flexible catheter tip ofclaim 1, wherein the inboard understructure includes a first proximalinboard mounting arm and second proximal inboard mounting arm thatextend along the tip longitudinal axis.
 3. The flexible catheter tip ofclaim 2, wherein the inboard understructure includes; a first inboardarm understructure that extends distally from the first proximal inboardmounting arm; and a second inboard arm understructure that extendsdistally from the second proximal inboard mounting arm.
 4. The flexiblecatheter tip of claim 3, wherein the inboard understructure includes aflared head portion connected to distal ends of the first and secondinboard understructure.
 5. The flexible catheter tip of claim 2, whereinthe outboard understructure includes a first proximal outboard mountingarm and a second proximal outboard mounting arm that extend along thetip longitudinal axis.
 6. The flexible catheter tip of claim 5, wherein:opposing faces of the first proximal inboard mounting arm and the firstproximal outboard mounting arm include a first set of frame locks; andopposing faces of the second proximal inboard mounting arm and thesecond proximal outboard mounting arm include a second set of framelocks corresponding to the first set of frame locks.
 7. The flexiblecatheter tip of claim 6, wherein the first set of frame locks and thesecond set of frame locks are configured to interlock with one another.8. The flexible catheter tip of claim 7, wherein the first set of framelocks include a plurality of interlocking tabs that extend from theopposing faces of the first proximal inboard mounting arm and the firstproximal outboard mounting arm and the second set of frame locks includea plurality of interlocking tabs that extend from the opposing faces ofthe second proximal inboard mounting arm and the second proximaloutboard mounting arm.
 9. The flexible catheter tip of claim 8, whereinthe plurality of interlocking tabs longitudinally alternate between: thefirst proximal inboard mounting arm and the first proximal outboardmounting arm and the second proximal inboard mounting arm and the secondproximal outboard mounting arm.
 10. The flexible catheter tip of claim1, wherein a distal end of the inboard understructure is connected to adistal end of the outboard understructure with a distal coupler.
 11. Theflexible catheter tip of claim 1, wherein the inboard understructure andthe outboard understructure are formed from nitinol.
 12. An integratedelectrode structure comprising: a catheter shaft comprising a proximalend and a distal end, the catheter shaft defining a catheter shaftlongitudinal axis; a flexible tip portion located adjacent to the distalend of the catheter shaft, the flexible tip portion comprising aflexible framework that includes: an inboard understructure, the inboardunderstructure including a first continuous element that includes afirst rectangular cross-section that extends along the shaftlongitudinal axis; an outboard understructure, the outboardunderstructure including a second continuous element that includes asecond rectangular cross-section that extends along the shaftlongitudinal axis; and a distal coupler that connects a distal end ofthe inboard understructure and a distal end of the outboardunderstructure.
 13. The integrated electrode structure of claim 12,wherein a proximal inboard portion of the inboard frame understructureand a proximal outboard portion of the outboard frame understructureeach include a frame lock portion.
 14. The integrated electrodestructure of claim 13, wherein the frame lock portion includes a tongueand groove structure.
 15. The integrated electrode structure of claim12, wherein a plurality of electrodes are disposed on the inboardunderstructure and the outboard understructure.
 16. A medical device,comprising: a catheter shaft comprising a proximal end and a distal end,the catheter shaft defining a catheter shaft longitudinal axis; aflexible tip portion, the flexible tip portion comprising a flexibleframework that includes: an inboard understructure, the inboardunderstructure including a pair of proximal inboard mounting armsmounted in the distal end of the catheter shaft, wherein each of theproximal inboard mounting arms include an inboard frame lock portion;and an outboard understructure, the outboard understructure including apair of proximal outboard mounting arms mounted in the distal end of thecatheter shaft, wherein each of the proximal outboard mounting armsinclude an outboard frame lock portion that corresponds with the inboardframe lock portion.
 17. The medical device of claim 16, wherein theinboard understructure includes: a pair of inboard arms that distallyextend from the pair of proximal inboard mounting arms; and a flaredhead portion connected to distal ends of the pair of inboard arms. 18.The medical device of claim 17, wherein the outboard understructureincludes: a pair of outboard arms that distally extend from the pair ofproximal outboard mounting arms; and a head portion connected to distalends of the pair of outboard arms.
 19. The medical device of claim 18,wherein the flared head portion and the head portion are connected via adistal coupler.
 20. The medical device of claim 18, wherein: alongitudinal width of the understructure that forms the head portion isless than a lateral width of the understructure that forms each one ofthe outboard arms; and a longitudinal width of the understructure thatforms the flared head portion is less than a lateral width of each ofthe understructure that forms each of the inboard arms.